So we are now a week away from Christmas and we are now a week away from the big day. We are getting into an even more accurate time frame now. Still using both the ECMWF forecast model and the GFS forecast model.

Sadly with long range forecasting things change quickly and the outlook for a white Christmas has changed quite a lot in recent days. We have gone from seeing the cold pattern to a weather front sweeping across the Western Isles bringing in warmer air. Its likely to still be cold before and after Christmas. But a white Christmas now looks less likely with temps in the in the high single figures. Also looks possibly a windy day with winds gusting 30 to 40 mph.
There is good model support from the GFS and the EC for this happening. Things again can still change between now and then. But this does highlight the challenges of long range forecasting.

So based on the latest model run information and the trends at this stage I am going to go for a 50% chance of Western Isles White Christmas.
Next update will be on Sunday evening.